package cn.base.day08;

public class Test01 {
    public static void main(String[] args) {
        //引用类型 用== 比的是地址
        String s1 = "abc";
        String s2 = "CBa";
        System.out.println(s1.equals(s2));
        s1.equalsIgnoreCase(s2);//忽略大小写
        //字符串是不可改变的
        String s3 = s1.toUpperCase();//转大写
        String s4 = s2.toLowerCase();//转小写
        System.out.println(s1);
        System.out.println(s3);
        System.out.println(s4);
        String a1 = "ABCD";
        String a2 = "A" + "B" + "C" + "D";//一个


    }
}
